UTTAR PRADESH JOURNAL OF ZOOLOGY

Therapeutic properties possessed by the plants enable them for the development new drugs with the least side effects. The current study was performed to evaluate the potential antimicrobial and phytochemical activities of Calotropis gigantea (L.) Dryand methanolic leaf extracts. The adjacent regions of Trivandrum district have been chosen for the collection of healthy and mature leaves of C. gigantea required for the investigation. Methanol extracts of plant leaves were prepared using a Soxhlet apparatus. The agar well diffusion method was utilised for the screening of antibacterial activity from the methanolic extracts of leaves. Using brine shrimp nauplii, the extracts were examined for the Brine Shrimp Lethality Bioassay. In the Brine Shrimp Lethality Bioassay, after 24 hours, the LC₅₀ value of the methanol extract of the C. gigantea leaves noted was 2667.1 µg/ml. Phytochemical screening of leaves revealed the presence of alkaloids, cardiac glycosides, saponins, flavonoids, reducing sugars and terpenoids in the most prominent amount, while tannins and steroids in lesser amounts. The results of the agar well diffusion method revealed that different concentrations of methanolic extracts showed better zone of inhibition against pathogenic microorganisms, Escherichia coli, Bacillus cereus, Staphylococcus aureus, Klebsiella pneumoniae and Vibrio cholerae. The highest zone of inhibition was noted against Staphylococcus aureus and Klebsiella pneumoniae. The results, therefore, established a good support for the use of C. gigantea in traditional medicine.